Sweden-Number/win32/except.c

168 lines
5.3 KiB
C

/*
* Win32 exception functions
*
* Copyright (c) 1996 Onno Hovers, (onno@stack.urc.tue.nl)
* Copyright (c) 1999 Alexandre Julliard
*
* Notes:
* What really happens behind the scenes of those new
* __try{...}__except(..){....} and
* __try{...}__finally{...}
* statements is simply not documented by Microsoft. There could be different
* reasons for this:
* One reason could be that they try to hide the fact that exception
* handling in Win32 looks almost the same as in OS/2 2.x.
* Another reason could be that Microsoft does not want others to write
* binary compatible implementations of the Win32 API (like us).
*
* Whatever the reason, THIS SUCKS!! Ensuring portabilty or future
* compatability may be valid reasons to keep some things undocumented.
* But exception handling is so basic to Win32 that it should be
* documented!
*
*/
#include <assert.h>
#include <stdio.h>
#include "windef.h"
#include "wingdi.h"
#include "winuser.h"
#include "winerror.h"
#include "ntddk.h"
#include "wine/exception.h"
#include "ldt.h"
#include "process.h"
#include "thread.h"
#include "stackframe.h"
#include "server.h"
#include "debugtools.h"
DEFAULT_DEBUG_CHANNEL(seh);
/*******************************************************************
* RaiseException (KERNEL32.418)
*/
void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
{
EXCEPTION_RECORD record;
/* Compose an exception record */
record.ExceptionCode = code;
record.ExceptionFlags = flags & EH_NONCONTINUABLE;
record.ExceptionRecord = NULL;
record.ExceptionAddress = RaiseException;
if (nbargs && args)
{
if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
record.NumberParameters = nbargs;
memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
}
else record.NumberParameters = 0;
RtlRaiseException( &record );
}
/*******************************************************************
* UnhandledExceptionFilter (KERNEL32.537)
*/
DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
{
struct exception_event_request *req = get_req_buffer();
char message[80];
PDB *pdb = PROCESS_Current();
/* send a last chance event to the debugger */
req->record = *epointers->ExceptionRecord;
req->first = 0;
req->context = *epointers->ContextRecord;
if (!server_call_noerr( REQ_EXCEPTION_EVENT )) *epointers->ContextRecord = req->context;
if (req->status == DBG_CONTINUE) return EXCEPTION_CONTINUE_EXECUTION;
if (pdb->top_filter)
{
DWORD ret = pdb->top_filter( epointers );
if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
}
/* FIXME: Should check the current error mode */
sprintf( message, "Unhandled exception 0x%08lx at address 0x%08lx.",
epointers->ExceptionRecord->ExceptionCode,
(DWORD)epointers->ExceptionRecord->ExceptionAddress );
MessageBoxA( 0, message, "Error", MB_OK | MB_ICONHAND );
return EXCEPTION_EXECUTE_HANDLER;
}
/*************************************************************
* SetUnhandledExceptionFilter (KERNEL32.516)
*/
LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
LPTOP_LEVEL_EXCEPTION_FILTER filter )
{
PDB *pdb = PROCESS_Current();
LPTOP_LEVEL_EXCEPTION_FILTER old = pdb->top_filter;
pdb->top_filter = filter;
return old;
}
/*************************************************************
* WINE_exception_handler
*
* Exception handler for exception blocks declared in Wine code.
*/
DWORD WINE_exception_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
CONTEXT *context, LPVOID pdispatcher )
{
__WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
return ExceptionContinueSearch;
if (wine_frame->u.filter)
{
EXCEPTION_POINTERS ptrs;
ptrs.ExceptionRecord = record;
ptrs.ContextRecord = context;
switch(wine_frame->u.filter( &ptrs ))
{
case EXCEPTION_CONTINUE_SEARCH:
return ExceptionContinueSearch;
case EXCEPTION_CONTINUE_EXECUTION:
return ExceptionContinueExecution;
case EXCEPTION_EXECUTE_HANDLER:
break;
default:
MESSAGE( "Invalid return value from exception filter\n" );
assert( FALSE );
}
}
/* hack to make GetExceptionCode() work in handler */
wine_frame->ExceptionCode = record->ExceptionCode;
wine_frame->ExceptionRecord = wine_frame;
RtlUnwind( frame, 0, record, 0 );
EXC_pop_frame( frame );
longjmp( wine_frame->jmp, 1 );
}
/*************************************************************
* WINE_finally_handler
*
* Exception handler for try/finally blocks declared in Wine code.
*/
DWORD WINE_finally_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
CONTEXT *context, LPVOID pdispatcher )
{
__WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
if (!(record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
return ExceptionContinueSearch;
wine_frame->u.finally_func( FALSE );
return ExceptionContinueSearch;
}